Interlocking stovepipe seam



Jan. 5, 1932. HAYMAN 1,839,674

-INTERLOCKING STOVEPIPE SEAM Filed March 20, 1930 6 4 5 6a 9 lizveni'or:

56 97 I Jia yman,

- MMDWWM Patented Jan. 5, 1932 PATENT; OFFICE EBER J. HAYMAN, OFPARKERSBURG, WEST VIRGINIA INTERLOCKING STOVEPIPE SEAM Application filedMarch 20, 1930. Serial N0. 437,417.

My present invention relates to improvements in interlocking means forthe edges of sheet-metal stovepipes or the like. An object of theinvention is to provide an interlocking seam for stovepipes which isreadily snapped into secure and permanent interlocking connection with aminimum of effort and labor and a maximum of security of connection andstrength.

A. further object is to provide an improved seam of reinforcedconstruction which is of such strength as to prevent accidentalseparation thereof without the necessity of clamping or hammering thefolds together and without the use of rivets.

Other objects will appear hereinafter.

The invention consists in the features, combination, and arrangement ofparts hereinafter described and particularly pointed out in the appendedclaims.

In the drawings,

Figure 1 is a cross sectional view of a sheet metal stove-pipe embodyingmy invention in position prior to being snapped into pipe form. I

Fig. 2 is a similar view of the parts in interlocking connection.

Fig. 3 shows diagrammatically the successive steps performed uponthemale section as by means of dies.

Fig. 4 shows diagrammatically the successive steps performed upon thefemale section as by means of dies Fig. 5 is a perspective view showingthe manner in which the stove pipe lock may be opened after it has beenlocked.

Fig. 6 is a view of a joint according to my invention, which has beenhammere Referring to the drawings, 1 represents the metallic sheet fromwhich the pipe section is formed. This sheet is bent transversely togenerally cylindricalshape. One marginal edge is bent inwardly uponitself as shown at 2 and then outwardly as shown at 3, the outwardlybent portion 3 extending beyond the reverse bend to form tongue 4. The.fold between 2 and 3 forms an inwardly facing locking shoulder 8. Thiscomprises the male portion of the joint.

The other marginal edge of said metallic sheet is pr-ovided with afemale formation comprismg an inwardly folded portion 5 and an outwardlyfolded portion 6 spaced from and providing a groove 7 with said inwardlyfolded portion 5 The outwardly folded portion 6 extends outwardly beyondthe mouth of the groove 7. The portion 6 from a point adjacent andslightly within the mouth of the groove 7 is of double Wall thickness.

The double wall consists of a terminal fold 6a bent inwardly and lyingagainst the surface of the outwardly folded portion 6. The folded outeror marginal edge of the double wall 6, 6a is bent upwardly andbackwardly to provide a locking flange 9. The double wall 6, 6:;including the doubled locking flange 9 provides a substantialreinforcement for the joint which materially strengthens it, preventscrushing in transit and straightening out of the locking flange 9 underheat and lateral strain, and thus prevents accidental separation of thejoint when in use.

In forming the joint the tongue 4 of the male member is inserted intothe groove 7 and the locking edge 8 is snapped into interlockingengagement within the locking flange 9. The entire portion 3 of the malemember including tongue 4 and edge 8 is then securely embraced withinthe pocket 10 defined by the shoulder 9 of the female member andincluding the groove 7 In Flgs. 3 and '4 are diagrammatically shown theeffect upon the male and female sections respectively of the successivebending and folding operations to which they are subjected in theirformation, as by means of dies. It will be obvious that some of theseoperations may be combined by suitable die arrangement, as for instance,the second and third operations in Fig. 4 may be combined and performedin one operation.

Fig. 5 shows the joint partially opened after having been closed orlocked. In this separation operation, preferably the plain end C of thefull joint pipe section is toward' the operator who, starting at theplain end, presses the seam A toward the opposite wall B of the pipe,with the wall B resting upon a flat surface thus causing the pipe toassume generally oval shape with the seam depressed.

In so doing the operator also exerts a separating strain on the lockwhich will begin to separate at the plain end. The -0 erator then shiftsor pushes his hands and ngers along the joint toward the crimped endD ofthe pipe maintaining the inward pressure and separating strain whichresults in complete separation of the-joint. A convenient and effectivemanipulation of this joint consists in placing the four fingers of eachhand adjacent the opposite sides of the seam as at E and F in Fig. 5,with the thumbs beneath the wall of the pipe as at G. The pressure andseparating strain is then readily applied to result in separation asshown at the plaln end in Fig. 5, at which time the thumbs are removedfrom beneath the pipe wall and the fingers are pushed along toward thecrimped end keeping up the pressure and separating strain. In this waycomplete separation 1s readily effected with a minimum of effort andtime and at the same time the joint is so constructed that when quicklysnapped into place it will be firmly locked.

It is desirable to provide a stovepipe joint which is capable of beinghammered if desired, as some buyers are prejudiced in favor of astovepipe joint which can be hammered. The-joint of the presentinvention possesses this advantage, since the parts are so formed thathammering does not destroy their eflicienoy nor impair the security ofthe lock. Folded shoulder 9 is so inclined and the space betweenportions 1 and 2 of the male portion is such that, if the joint ishammered, the fold 9 will be forced into and will be firmly imbedded inthis space to make the hammered joint secure. This is shown in Flg. 6.

I claim:

1. In a stovepipe, a sheet of metal one marginal edge of which isprovided with a male formation comprising an inwardly folded portion andan outwardly folded portion providing an inwardly disposed locking edgeand a locking tongue, the other marginal edge of said metallic sheetbeing provided with a female formation comprising an inwardly foldedportion and an outwardly folded portion spaced from and providing agroove with said inwardly folded portion, said outwardly folded portionextending outwardly beyond the mouth of the groove and having a lockingflange at its outer end, said outwardly folded portion being of doublewalled thickness from and beyond a point adjacent the mouth of saidgroove, said tongue being receivable in said groove with said lockingflange and locking edge in interlocking engagement.

2. A stovepipe according to claim 1 in which said double-walledthickness is ormed by a terminal fold portion folded inwardly from thetop of said locking flange and ly-.

ing against the inner side of said flange and against the said extendedoutwardly folded portion, the inner edge of said terminal inward foldbeing disposed within the mouth of the groove.

3. An interlocking stovepipe seam comprising a male formation along oneedge consisting of a reversely bent edge providing a locking'edge and atongue, a female formation along the other edge consisting of areversely bent edge providing spaced walls enclosinga groove and,extending beyond a point adjacent the mouth of the groove in double wallthickness, said double wall extension being bent to provide a terminallocking flange forming a pocket including said groove for receiving thetongue and locking edge of said male formation.

4. In a stovepipe, a sheet of metal one marginal edge of which is foldedback upon itself .to lie against the outside of the sheet and to form adouble wall, said sheet immediately inwardly of said double wall beingdoubled upon itself to form a groove adjacent said double wall, themarginal edge of said double wall being bent outwardly and backwardly toprovide a doubled locking flange defining the marginal limit of a pocketincluding said groove, the other margin of said sheet being adapted tobe inserted in said pocket and being-doubled upon itself Within themarginal edge to provide an inwardly disposed locking edge to engage thesaid doubled looking flange.

5. A stovepipe construction according to claim A in which the innermargin of said double wall is disposed slightly within the mouth of saidgroove formed by the sheet being doubled upon itself.

6. A stovepipe joint comprising a female formation along one edgeconsisting of a reversely bent edge providing spaced walls en closing agroove and extending beyond a point adjacent the mouth of the groove indouble wall thickness, said double wall extension being bent to providea terminal looking flange forming a pocket including said groove, a maleformation along the other edge consisting of a reversely bent edgeproviding an inwardly facing locking edge and a tongue, said tonguelying in the said groove with the said locking flange and locking edgein engagement, said reversely bent male formation providing a spacebetween its folded walls above its locking edge, and said locking flangebeing inclined with its edge in position to be forced into said space ifthe joint should be flattened as by hammering.

In testimony whereof, I aifix mysignature.

' EBER J. HAYMAN.

